Levothyroxine: Conventional and novel drug delivery formulations

Development and In Vivo Evaluation of Sustained Release Microparticles Loaded with Levothyroxine for Hypothyroidism Treatment

Hypothyroidism is a chronic condition combated by a daily oral supplementation of levothyroxine. In addition to the need for frequent dosing, oral administration may result in variable absorption of the drug leading to a failure in achieving normal thyroid function. Therefore, the development of a long-acting injectable system capable of delivering the drug is necessary. This work was aimed at developing sustained release microparticles loaded with levothyroxine. The microparticles were produced through the emulsification-solvent evaporation method using 2 grades of biocompatible and biodegradable polyesters: poly(ᴅ,ʟ-lactide-co-glycolide) (PLGA) and poly(ᴅ,ʟ-lactide) (PLA). Both polymers produced microparticles with very similar sizes (1.9 µm) and zeta potential values (around -22.0 mV). However, PLA microparticles had a significantly higher drug loading (6.1% vs. 4.4%, respectively) and encapsulation efficiency (36.8%, vs. 26.1%, respectively) when compared to PLGA counterparts. While both types of microparticles displayed a biphasic release pattern in vitro, a slower rate of release was observed with PLA microparticles. Moreover, a similar biphasic release pattern was found in vivo, with an initial phase of rapid release followed by a slower phase in the subsequent 10 days. These results indicate the possibility of developing levothyroxine loaded polyester microparticles as a potential long-acting thyroid hormone replacement therapy.

Examining the Effects of Nutrient Supplementation on Metabolic Pathways via Mitochondrial Ferredoxin in Aging Ovaries

As women age, oocytes are susceptible to a myriad of dysfunctions, including mitochondrial dysfunction, impaired DNA repair mechanisms, epigenetic alterations, and metabolic disturbances, culminating in reduced fertility rates among older individuals. Ferredoxin (FDX) represents a highly conserved iron-sulfur (Fe-S) protein essential for electron transport across multiple metabolic pathways. Mammalian mitochondria house two distinct ferredoxins, FDX1 and FDX2, which share structural similarities and yet perform unique functions. In our investigation into the regulatory mechanisms governing ovarian aging, we employed a comprehensive multi-omics analysis approach, integrating spatial transcriptomics, single-cell RNA sequencing, human ovarian pathology, and clinical biopsy data. Previous studies have highlighted intricate interactions involving excessive lipid peroxide accumulation, redox-induced metal ion buildup, and alterations in cellular energy metabolism observed in aging cells. Through a multi-omics analysis, we observed a notable decline in the expression of the critical gene FDX1 as ovarian age progressed. This observation prompted speculation regarding FDX1's potential as a promising biomarker for ovarian aging. Following this, we initiated a clinical trial involving 70 patients with aging ovaries. These patients were administered oral nutritional supplements consisting of DHEA, ubiquinol CoQ10, and Cleo-20 T3 for a period of two months to evaluate alterations in energy metabolism regulated by FDX1. Our results demonstrated a significant elevation in FDX1 levels among participants receiving nutritional supplementation. We hypothesize that these nutrients potentiate mitochondrial tricarboxylic acid cycle (TCA) activity or electron transport chain (ETC) efficiency, thereby augmenting FDX1 expression, an essential electron carrier in metabolic pathways, while concurrently mitigating lipid peroxide accumulation and cellular apoptosis. In summary, our findings underscore the potential of nutritional intervention to enhance in vitro fertilization outcomes in senescent cells by bolstering electron transport proteins, thus optimizing energy metabolism and improving oocyte quality in aging women.

One sip of water with LT-4 supplementation-a key to euthyroidism in Hashimoto's thyroiditis

PURPOSE

Recommended pharmacotherapy for hypothyroidism in Hashimoto's thyroiditis (HT) is oral supplementation with levothyroxine (LT-4). However, serum thyrotropin (TSH) levels within normal range are not consistently achieved with LT-4 medication.

PATIENTS AND METHODS

We report on 35 HT patients with LT-4 therapy in this retrospective evaluation. In general, we recommend that a maximum of two sips of water, which would then amount to < 50 mL, be ingested at the same time as LT-4. We report on follow up examinations measuring TSH and antibodies against thyroid peroxidase (TPOAb) after 6 months to five years.

RESULTS

After median time of 643 days (range 98-1825) we found in 35 HT patients a statistical significant reduction of serum TSH (p < 0.001) and TPOAb (p = 0.006). The patients median body weight was 71 kg (range 48-98) and a daily LT-4 dosage was used with median 69.1 µg (range 25-150). This results in a daily LT-4 dose of median 1.01 µg/kg bodyweight (range 0.3-2.3).

CONCLUSIONS

The reduction of water ingestion to a maximum of two sips, which is <50 mL, combined with LT-4 supplementation helps to achieve euthyroidism in HT. In addition, it reduces the L-T4 medication dosage needed to lower TSH serum levels and decreases TPO antibodies in HT.

Thyroid Troubles: A Case of Hypothyroidism-Associated Recurrent Massive Pleural Effusion

Pleural effusions can be secondary to several different etiologies. Sometimes, they can be related to hypothyroidism. We present a case of massive pleural effusion resulting from hypothyroidism. A 75-year-old male with a history of liver cirrhosis, hypothyroidism, and medication non-adherence presented to the emergency department (ED) with shortness of breath and altered mental status. Physical exam and chest imaging were consistent with right-sided pleural effusion. Effusion was exudative. Multiple recurrences complicated the hospitalization despite thoracentesis and pleurodesis. Labs revealed hypothyroidism, and finally, the patient was started on hormone replacement, resulting in the resolution of the effusion. Pleural effusion is a rare manifestation of hypothyroidism, thought to be mediated by vascular endothelial factors. Pleural fluid analysis shows both exudative and transudative patterns. Hormonal replacement is the mainstay of treatment. Clinicians need to be aware of the rare etiologies of pleural effusion. Depending on the patient's presentation, due work-up should be done to ensure a timely diagnosis and management.

Efficacy and safety of Wuhu oral liquid in treating acute soft tissue injuries: a multicenter, randomized, double-blind, double-dummy, parallel-controlled trial

Background: Wuhu Oral Liquid (WHOL) is a modified preparation derived from the famous Wuhu Powder, which has a long history of use in treating traumatic injuries. This preparation has anti-inflammatory and analgesic properties and accelerates recovery following acute soft tissue injuries. Aims: To evaluate the efficacy and safety of WHOL in treating acute soft tissue injury associated with qi stagnation and blood stasis syndrome and to provide a basis for applying for the protection of varieties of Chinese medicine for WHOL. Methods: This study was a randomized, controlled, double-blind, multicenter clinical trial in which Fufang Shang Tong Capsule (FFSTC) was selected as the control drug. A total of 480 subjects with acute soft tissue injury associated with qi stagnation and blood stasis syndrome were randomly divided into a test and control group in a 3:1 ratio. The duration of drug treatment was 10 days. The primary outcome was Visual Analogue Scale (VAS) score for pain (including pain at rest and pain on activity). Secondary outcomes included the disappearance time of the pain at rest and on activity; the curative effect of TCM syndrome and improvement in the individual symptoms of TCM (swelling, ecchymosis, and dysfunction); and changes in C-reactive protein (CRP) and interleukin-6 (IL-6) levels. Safety was assessed using vital signs, laboratory examinations, electrocardiograms, and physical examinations. Results: Patient compliance was satisfactory in both groups (all between 80% and 120%). After 4 days of treatment, the WHOL group was superior to the FFSTC group in decreasing the VAS scores for pain at rest (-1.88 ± 1.13 vs. -1.60 ± 0.93, p < 0.05) and on activity (-2.16 ± 1.18 vs. -1.80 ± 1.07, p < 0.05). After 7 days of treatment, the WHOL group was superior to the FFSTC group in decreasing the VAS scores for pain on activity (-3.87 ± 1.60 vs. -3.35 ± 1.30, p < 0.01) and improving swelling (cure rate: 60.4% vs. 46.2%, p < 0.05; obvious effective rate: 60.7% vs. 47.0%, p < 0.05). After 10 days of treatment, the WHOL group was superior to the FFSTC group in decreasing the levels of CRP (-0.13 ± 2.85 vs. 0.25 ± 2.09, p < 0.05) and improving the TCM syndrome (cure rate: 44.1% vs. 30.8%, p < 0.05) and swelling (cure rate: 75.6% vs. 67.5%, p < 0.01; obvious effective rate: 75.6% vs. 68.4%, p < 0.05; effective rate: 77.0% vs. 71.8%, p < 0.05). The disappearance time of pain at rest was 8 days in both groups and 9 days on activity in both groups. In addition, there was no statistical difference between the incidence of adverse events (4.5% vs. 2.6%, p > 0.05) and adverse reactions (0.3% vs. 0%, p > 0.05) between the WHOL group and the FFSTC group. No serious adverse events occurred in either group, and no subjects were withdrawn because of adverse events. Conclusion: WHOL relieves the symptoms caused by acute soft tissue injury associated with qi stagnation and blood stasis syndrome more rapidly than FFSTC, and it is effective and safe in the treatment of acute soft tissue injury. Future studies still need a larger sample size to verify its efficacy and safety. Clinical Trial Registration: https:// www.chictr.org.cn/showproj.html?proj=149531, Identifier ChiCTR2200056411.

Refractory Hypothyroidism: Unraveling the Complexities of Diagnosis and Management

INTRODUCTION

Refractory hypothyroidism (RH) represents a challenge in the diagnosis and treatment within the field of thyroidology. It is defined as the inability to achieve disease control despite using levothyroxine (LT4) doses of 1.9 μg/kg/d or higher.

METHODS

A comprehensive review, encompassing 103 articles, was conducted using the Scielo, Scopus, and EMBASE databases, providing an approach to evaluation and diagnosis of this condition.

RESULTS

LT4 disintegrates and dissolves within an acidic gastric environment before being absorbed in the jejunum and ileum. It then extensively binds to serum transporter proteins and undergoes deiodination to yield tri-iodothyronine, the biologically active hormone. There are various nonpathological causes of RH, such as noncompliance with treatment, changes in the brand of LT4, food and drug interferences, as well as pregnancy. Pathological causes include lactose intolerance, Helicobacter pylori infection, giardiasis, among others. The diagnosis of RH involves conducting a thorough medical history and requesting relevant laboratory tests to rule out causes of treatment resistance. The LT4 absorption test allows for the identification of cases of malabsorption. The treatment of RH involves identifying and addressing the underlying causes of noncompliance or malabsorption. In cases of pseudomalabsorption, supervised and weekly administration of LT4 may be considered.

DISCUSSION

Early recognition of RH and correction of its underlying cause are of utmost importance, as this avoids the use of excessive doses of LT4 and prevents cardiovascular and bone complications associated with this condition.

Medications and Food Interfering with the Bioavailability of Levothyroxine: A Systematic Review

Purpose

Levothyroxine is a common prescribed drug. Many medications and food, however, can interfere with its bioavailability. The aim of this review was to summarize the medications, food and beverages that interact with levothyroxine and to assess their effects, mechanisms and treatments.

Methods

A systematic review on interfering substances that interact with levothyroxine was performed. Web of Science, Embase, PubMed, the Cochrane library, grey literature from other sources and the lists of references were searched for human studies comparing the levothyroxine efficacy with and without interfering substances. The patient characteristics, drug classes, effects and mechanism were extracted. The NHLBI study quality assessment tools and the JBI critical appraisal checklist were used to assess the quality of included studies.

Results

A total of 107 articles with 128 studies were included. Drugs interactions were revealed in calcium and iron supplements, proton pump inhibitors, bile acid sequestrants, phosphate binders, sex hormones, anticonvulsants and other drugs. Some food and beverage could also induce malabsorption. Proposed mechanisms included direct complexing, alkalization, alteration of serum thyroxine-binding globulin levels and acceleration of levothyroxine catabolism via deiodination. Dose adjustment, administration separation and discontinuation of interfering substances can eliminate the interactions. Liquid solutions and soft-gel capsules could eliminate the malabsorption due to chelation and alkalization. The qualities of most included studies were moderate.

Conclusion

Lots of medications and food can impair the bioavailability of levothyroxine. Clinicians, patients and pharmaceutical companies should be aware of the possible interactions. Further well-designed studies are needed to provide more solid evidence on treatment and mechanisms.